FusionDex

Klefpod forms its cocoon of steel fibers around a single large key. It is impossible to remove this key until Klefpod either evolves or unfuses, so some Trainers simply hang Klefpod from their belt so that they can still use the key.

Its shell is as hard as an iron slab. It never lets go of a key that it likes, so people give it the keys to vaults and safes as a way to prevent crime.